新生期卡介苗和乙肝疫苗联合接种对哮喘小鼠IFN-γ、IL-4和IL-17A表达的影响

目的:观察新生期卡介苗(BCG)和乙肝疫苗(HepB)联合接种对哮喘小鼠干扰素γ(IFN-γ)、白细胞介素4(IL-4)和白细胞介素17A(IL-17A)表达的影响,探讨BCG和HepB联合接种对气道炎症的影响及可能机制。方法:BALB/c小鼠随机分为BCG和HepB联合接种造模卵清蛋白(OVA)所致哮喘模型]组(B/H/O组)、BCG接种造模组(B/O组)、HepB接种造模组(H/O组)、BCG和HepB联合接种组(B/H组)、造模组(OVA组)、BCG组、HepB组和生理盐水对照(NS)组,每组6只。B/H/O组和B/H组于第0、7和14天分3次皮下注射1×105CFU的BCG,同时第0和28天分2次下肢腿部肌肉注射HepB 1.5μg,其它组单独接种BCG或HepB。OVA致敏和雾化吸入激发建立哮喘模型;末次激发24 h后取肺组织HE染色;收集支气管肺泡灌洗液(BALF)进行细胞总数计数和嗜酸性粒细胞(EOS)计数;ELISA法检测血清IFN-γ和IL-4及肺组织匀浆IL-17A的水平。结果:肺组织病理观察发现,OVA组、B/O组、B/H/O组和H/O组支气管周围大量炎症细胞浸润,气道上皮细胞增生肥大,B/H/O组和H/O组的炎症程度较OVA组重,B/O组则较OVA组轻。B/H/O组、B/O组和H/O组BALF细胞总数与OVA组比较均下降(P0.05);EOS计数在B/H/O组比B/H组上升(P0.05),B/O组比BCG组上升(P0.05),H/O组比HepB组上升(P0.05)。分别与H/O组、OVA组和NS组比较,HepB组的血清IFN-γ/IL-4比值均升高(P0.05);分别与B/H/O组、B/O组、OVA组和NS组比较,B/H组的血清IFN-γ/IL-4比值均升高(P0.05)。与OVA组比较,B/H/O组和B/O组的肺组织匀浆IL-17A水平均下降(P0.05);与B/O组比较,B/H/O组的肺组织匀浆IL-17A水平进一步下降(P0.05)。结论:卡介苗和乙肝疫苗联合接种有助于减轻哮喘模型小鼠肺部的炎症反应,其机制可能与降低IL-4分泌、提高IFN-γ/IL-4水平和抑制IL-17A的表达有关。

Expression of IFN-γ, IL-4 and IL-17A in asthmatic mice vaccinated with BCG and HepB in neonatal period

AIM: To investigate the expression of IFN-γ, IL-4 and IL-17A in asthmatic mice vaccinated with bacillus Calmette-Guérin (BCG) and hepatitis B (HepB) in the neonatal period. METHODS: BALB/c mice were randomly divided into BGG+HepB+ovalbumin (OVA) group (B/H/O group), B/O group, H/O group, B/H group, OVA group, BCG group, HepB group and normal saline (NS) group (n=6). The mice in B/H/O group and B/H group at 0, 7 and 14 d received subcutaneous injection of 1×10⁵ CFU BCG for 3 times, while at 0 and 28 d received intramuscular injection of 1.5 μg HepB on the hindlimb twice. The mice in other groups were individually vaccinated with BCG or HepB. OVA sensitization and aerosol inhalation were performed to establish the asthma model. The lung tissues were collected for HE staining. Bronchoalveolar lavage fluid (BALF) and peripheral blood (PB) were collected, and the number of eosinophils (EOS) in BALF was counted. The serum levels of IFN-γ and IL-4, and the level of IL-17A in lung tissue homogenate were measured by ELISA. RESULTS: The pathological changes of the lung in OVA group, B/O group, B/H/O group and H/O group were observed. There were extensive inflammatory cell infiltration around the bronchus, and epithe-lial cell hypertrophy. Those in B/H/O group and H/O group were worse than those in OVA group, while those in B/O group was better than those in OVA group. Total BALF cell counts in B/H/O group, B/O group and H/O group were decreased (P<0.05) as compared with OVA group. The BALF EOS count in B/H/O group was higher than that in B/H group, that in B/O group was higher than that in BCG group, and that in H/O group was higher than that in HepB groups (P<0.05). Compared with H/O group, OVA group and NS group, the serum IFN-γ/IL-4 ratio in HepB group was increased (P<0.05), and compared with B/H/O group, B/O group, OVA group and NS group, that in B/H group was also increased (P<0.05). Compared with OVA group, the level of IL-17A in the lung tissues of B/H/O group and B/O group was decreased (P<0.05), and compared with B/O group, that in B/H/O group was further decreased (P<0.05). CONCLUSION: Combined vaccination of BCG and HepB reduces the inflammotory responses in the lung tissues of asthmatic mice. The mechanism may be related with the decrease in the release of IL-4, the increase in IFN-γ/IL-4, and the inhibition of IL-17A expression.